John w



(No Model.)

J. W. HYATT.

CEMENT FILTER.

No. 369,718. Patented Sept. 13. 1887.

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UNITED STATES I PATENT OFFICE;

JOHN. w. HYATT, oF EWARK, NEW JERSEY ASSIGNOR TO THE HYATT PURE WATER COMPANY, o smun PLAOE. 3 v

CEM ENT FILTER.

SPBCIFICATION forming part of Letters Ptent No. 369.718, datedseptembe' 13, 1887.

' Application filed January 3, 1887.

` needed water to the cement without stirring particles before such wetting. I the-efore asslowly through the same.

certai ned the means necessary to set or harden the 'cement without agitation, and find that the pores then remain open sufliciently to form the substance into a filter plate or bed of very fine and perfect character, and the bulk of the cement remaining substantially the same as when in powder. Two means for thus hardening the cement are shown herein, one consisting in the use of porous paper between the cement and a layer of water and the other in a'steam box or chamber in which the cement is gradually noistened, e x i t e The annexed drawings show these different means for thus hardening the cement, Figura 1 being a vertical section of a mold resting upon a bed-plate, and Fig; 2 being a vertical section of a mold inclosed in a s'team-box. a

In Fig. 1 A is the mold, formed with open bottom and resting-upon a packing-ring', B, ,on a bed-plate, C. D is a layer of cement packed in the bottom of the mold to the re- 'quired thickness. E is a layer of blottingpaper or porous fabric resting upon the surface of the cement, and F 'is a layer of water `pourcd over the porous fabric to percolate I have found that when a part only of the needed water is allowed to thus slowly percolate. into the cement without agitation the latter becomes Serial No. 223.287. (No morlel.)

gradually moistenedyjthoutsettling, and is 'consolidatedi a porous plate or block,

through which water may be readily filtered;

It is well known that hydraulic cement is impervious to moisture or fluid when stirred with water and then allowed to set, and the porous character of the cement when treated by my process is secured by applying .to the cement only suificient water to attach the particles together without floating any of them in fluid or causing them to flow into closer contact with one another.` Such partial wetting of the cement hardens the material sufficiently in about a day s time to retain its porous character whenmppliedwith the remainder of the water of crystallizati' ecesary to'fully hy- As cement requires a larger quantity of water to fully hydrate it than is necessary to make it retain a fixed form,it is plain that the first essential of my process is to limit the quantity of water applied below the hydrating point, and to set or harden the cement in a 'porous state before applying the :remainderi The second essential is to apply the moisture slowly and without agitation, to avoid moving the particles into close contact. *While a porous pad, like the paper E, thus applies the fluid,it may be otherwise applied,as shown iu Fig. 2, which isa kind of vapor bath. In this figure, G are molds for the cement, and H is a steam box or casing provided with a cover, I, to retain steam in contact with the ce ent. The steam may be generated by placng water, J in the box around the mold and heating the box to vaporize itor the vapor may be furv nishdbateam-j et. The vapor when raised from the water is absorbed by the cement,and the latter is hardened by a liberal wetting with water after it is thus moistenedand solidified without the change of bulk and closing of its A pores that results when the cement is fully wet and stirred. v

Other means may obviously be devised to moisten the cement without agitation, as by 93 throwing a fine spray upon the surface of the cement from a vaporizer or by other suitable means.

terstices between such particlcs must correspondingly vary. To constitute a fine' filtering medium the coarser particles may be sifted or otherwise removed from the cement (as by regrinding) and the remainde' treated with moisture, as herein described.

The filter-plates formed by my invention are so finethat the impnrities are deposited wholly upon the surface, and the bed is therefore readily and effectively cleansed by a surface washing. I do not, therefore, limit myself to any special means of carrying into efi`eet my discove'y and in vention.

I disclaim herein the porous composition formed of hydranlic cement with the finer particles removed, as I have claimed the same in my prior patent application, No. 221,(378, filed December 15, 1886.

I may remove the coarser partieles in practicing my present invention; but in any case the material I use would consist mainly of the finer particles and my methods operate to harden the same with the natural interstices between them.

The filter plates or beds formed by my process may be used in any suit-able receptacle or casing,and it is obvious that a filter-bed may be thus formed in the bottom of a reservoi' or receptacle, where it would remain in performing its intended functions.

Having thns set forlh my invention, what I claim is- 1. The method herein described for forming porous filter plates or beds of hydraulic cement, consisting in the application to the cement of a part of the water of crystallization; secondly, in the partial hardening of the same in a porous condition, and, thirdly, in the application of the remainder of the water required to hydrate the cement, as and for the purpose set forth. a

2. The method of forming porons filter beds or plates of hydraulic cement, which consists in the slow and gradual application of moisture to the cement without agitation, as and for the purpose set forth.

3. The method of forming porous filter beds or plates of hydranlic cement, consisting in the slow and gradual application of vapor or spray to the cement, as and for the purpose set forth.

In testimony whereof I have herennto set my hand in the presence of two subscribing witnesscs.

JOHN W. HYATT.

Witnesses FRANK L. MoUToN, THOS. S. CRANE. 

